Behaviour of micropiles in heterogeneous coarse soils

This paper reports on an experimental investigation on the behaviour of small-diameter piles, commonly referred to as micropiles. This particular type of deep foundation is frequently used in many barely accessible Italian mountainous areas, often characterised by complex ground profiles composed of mixtures of coarse soils with some fine matrix elements including cobbles and large-diameter boulders. In such ground conditions, the lack of reliable site and laboratory geotechnical investigations providing an accurate soil mechanical description and conservative approaches for micropile design often lead to significant underestimation of the vertical ultimate load. In order to improve micropile design in such geological contexts, a new field trial investigation involving tension and compression load tests on micropiles up to failure was set up in a selected test site located in the Italian alpine region. From interpretation of the load tests carried out so far, the reliability of commonly used calculation methods for estimating bearing capacity is discussed. As a result, a new approach for a more suitable calculation of the mobilised shaft and base resistance of micropiles bored in highly coarse soils is tentatively propos

Experimental study on the hydro-mechanical behavior of soils improved using the CSM technology

Deep Mixing Methods (DMMs) can be regarded as constantly evolving technologies for improving soil properties in order to satisfy predefined design requirements. Their applications are very common in geotechnical engineering and, in some cases, they can be conveniently selected instead of more traditional techniques. Despite DMMs are customarily used to strengthen soft soils like peats, clays, and silts, they can also be used very effectively in various subsoil configurations for several purposes, as, for instance, in the case of soil liquefaction prevention or cut-off/retaining walls. Even if soil mixing practice has become very consolidated in geotechnical engineering and numerous researchers in the past have tried to develop predictive equations taking into account the more relevant factors affecting the strength of DM constructions, i.e. influence of binder, soil, mixing and curing conditions, there is still no widely applicable formula for the estimation of the field strength characterized by a reasonable level of accuracy. Predictions are normally based on the mechanical behaviour of laboratory prepared mixtures, which, most of the time, significantly differ from in-situ treated soils due to the specific mixing, curing, and subsoil conditions encountered at the site. Technical standards were recently developed to provide general guidelines for the production of good quality laboratory mixed soil samples. Similarly, other codes concerning the critical deep mixing site construction aspects were introduced in several counties in order to improve the quality assurance and quality control (QA/QC) programmes conceived to verify the treatment effectiveness. However, a direct correlation between laboratory and field mixing performance is still far from being described, probably owing to the lack of a sufficient number of well documented case histories. In this research, a comparison tool between laboratory and field procedures has been tentatively deduced from energetic considerations depending on mixing efforts transferred to the soil to be treated using different devices. This thesis mainly focuses on the results of a comprehensive experimental investigation carried out on treated soil mixtures collected from several worldwide jobsites in which the Cutter Soil Mixing (CSM) technology was used. CSM, launched since 2003, is a recent and efficient system that, besides other DMMs, has the advantage of a high level of process control providing detailed information regarding the in-situ mixing method. The elaboration of these data, which significantly support the usual QA/QC procedures, has been used to define a new easily determinable site parameter closely related to the mixing efficacy, which, in turn, greatly influences the performance attained. As other DM methods, CSM produces some amount of spoil material, which is deemed to contain part of the binder introduced into the soil to activate hydration reactions once combined with both water and minerals in the ground. Since no estimation methods are available to evaluate the binder loss, an approximate amount of binding material is customarily added and mixed with the natural soil, hampering the performance prediction. To remedy this situation, a new formulation has been proposed to estimate the binder loss and to compute a more proper cement content. During the research activity, mechanical, hydraulic, mineralogical, and micro-structural tests were carried out in order to describe in detail the behaviour of the CSM treated material from different points of view and to acquire a reliable picture of the main factors affecting the relevant properties of stabilized soils. The obtained test results allowed to develop a new mathematical model for the evolution of the mechanical strength of granular and cohesive soils treated with the CSM technique as a function of the specific site conditions. The defined procedure has proved to be very effective in the major part of the case histories considered in this work

Psychological factors underlying adherence to COVID-19 regulations: A commentary on how to promote compliance through mass media and limit the risk of a second wave

Considering the possibility of a second wave of the COVID-19 pandemic, this brief commentary is intended to share some suggestions on how to phrase public health advice about maintaining social distancing, using face masks in public spaces and adhering to personal hygiene measures. The discussion will be focused on three factors: empathy, positive mood and social influence. The commentary concludes with a series of brief suggestions aimed at policy makers and stakeholders involved in promoting adherence to regulations to avoid a second wave of the pandemic through mass media communications.</p

Overcoming Metabolic Burden in Synthetic Biology: a CRISPR interference approach

Synthetic Biology is gaining an increasingly important role in the scientific community and dedicated research centers are rising all over the world. This discipline introduced the engineering principles of abstraction, modularity and standardization in the biology world; the application of these principles is allowing the design of complex biological systems to program living cells, realizing all sorts of desired function in many fields. These systems consist of DNA sequences, rationally combined to program the genetic instructions for cell behavior customization. Each part should behave as a biological brick for the design of complex genetic programs through functional building blocks; each module undergoes an extensive characterization to provide documentation on its functioning, enabling the rational design of complex circuits. Mathematical modeling accompanies all the design procedure as a tool to describe the behavior of each single genetic module, in a bottom-up fashion that should allow the prediction of more complex systems obtained by the interconnection of pre-characterized parts. However, many unpredictability sources hamper the ideally rational design of those synthetic genetic devices, mainly due to the tangled context-dependency behavior of those parts once placed into an intrinsically complex biological living system. Among others, the finite amount of translational resources in prokaryotic cells leads to an effect called metabolic burden, as a result of which hidden interactions between protein synthesis rates arise, leading to unexpected counterintuitive behaviors. To face this issue, two actions have been proposed in this study: firstly, a recently proposed mathematical modeling solution that included a description of the metabolic load exerted by the expression of recombinant genes have been applied on a case study, highlighting its worth of use and working boundaries; second, a CRISPR interference-based architecture have been developed to be used as an alternative to high resource usage transcriptional protein regulators, studying the underlying mechanism in several circuital configurations and optimizing each forming part in order to achieve the desired specifications. In Chapter 1, an introduction on synthetic biology is presented; in the second part, a brief overview on CRISPR technology and the overall aim of the study are reported. In Chapter 2, a case study evaluating the use of mathematical modeling to properly include metabolic burden in rational design of a set of transcriptional regulator cascades is reported. Firstly, the circuits and expected behavior are introduced, along with the discussion about experimental data, dissenting from what initially predicted. Secondly, the comparison between the use of a classical Hill equation-based model and an improved version that explicitly consider the translational load exerted by the expression of recombinant genes is reported. In Chapter 3, the design and deep characterization of a BioBrick$^{TM}$-compatible CRISPR interference-based repression set of modules is shown; expression optimization of the molecular players is reported and its usability as a low-burden alternative is demonstrated with experimental data and mathematical modeling. Working boundaries, peculiar aspects and rooms for improvements are then highlighted. In Chapter 4, preliminary studies aimed to improve the CRISPR interference system are reported and some of its context-dependencies are highlighted. Effects on repression efficiency due to alteration in the sequence of the RNA molecules addressing the CRISPR machinery to the desired target are discussed; evaluation of problems and opportunities related to the expression of more of this RNA guides are then highlighted. Lastly, an example of behavior of the system in presence of a competitor transcriptional regulator is reported. In Chapter 5 the overall conclusions of this thesis work are drawn

An investigation of autonomic arousal and attentional mechanisms in children with ADHD and Autism

The present doctoral project was aimed at investigating the impact of Attention Deficit Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD) on measures of physiological arousal, alerting/vigilance, attention orienting and executive functions. 106 children between 7 and 15 years of age (31 typically developing; 24 ADHD-only; 18 ASD-only; 33 ADHD&ASD) performed a battery of eye-tracking and EEG experimental paradigms, while parent-reported measures were used to evaluate the severity of symptoms of ASD, ADHD and other psychiatric conditions. Children with clinical diagnoses of ADHD and ASD showed condition-specific signs of dysregulated physiological arousal and vigilance, with ADHD more likely to be associated with difficulties in up-regulating and maintaining an optimal level of vigilance to the environment, and ASD more associated with over-reactivity to sensory information and difficulties in down-regulating autonomic arousal in line with contextual demands. We also demonstrated that executive function and cognitive control mechanisms are likely to be less effective in children with comorbid ADHD+ASD, with negative effects on performance accuracy. In the discussion of this dissertation, some suggestions for clinical practice and future research studies, besides a description of the implications of the findings on the everyday life of people with ADHD and/or ASD, are provided

The everyday life of people living with the chronic condition of diabetes mellitus

The objective of this study was to understand the experience of a person with diabetes mellitus and how that person deals with adversity in everyday life. Data collection was performed by means of a Focal Life History questionnaire and by observing health care professionals. Data analysis was based on the comprehensive approach, which permitted understanding the everyday life as a scenario for those living with the experience of falling ill and searching for care, considering that this experience is unique and personal. It is impossible to create health care practices that disregard the everyday life and health situation of the person. Furthermore, it is impossible to propose such practice without the active participation of the person affected by those decisions and conducts.Este estudio objetivó comprender la experiencia de enfermarse de una persona en condición crónica de diabetes mellitus y la manera como esta enfrenta las adversidades en su cotidiano, cuyo corpus de datos fue obtenido a través de la Historia de Vida Focal y de la observación de prácticas profesionales de atención. El análisis de los datos tuvo como fundamento el abordaje comprensivo, que nos permitió entender lo cotidiano como el gran escenario para quien vivencia la experiencia de enfermarse y de buscar cuidados, siendo que el modo como cada persona la vivencia es única e individual. Así, no es posible construir prácticas profesionales de cuidado no consideren la situación cotidiana de vida y salud de la persona a ser cuidada. Como también no es posible proponer esas prácticas sin la participación activa de la persona sobre la cual irán incidir las decisiones y conductas allí tomadas.Este estudo objetivou compreender a experiência de adoecimento de uma pessoa em condição crônica do diabetes mellitus e a maneira como esta enfrenta as adversidades no seu cotidiano, cujo corpus de dados foi obtido através da História de Vida Focal e da observação de práticas profissionais de atenção. A análise dos dados foi embasada na abordagem compreensiva, que nos permitiu entender o cotidiano como o grande cenário para quem vivencia a experiência de adoecimento e a busca por cuidados, sendo que o modo como cada pessoa a vivencia é única e individual. Assim, não é possível construir práticas profissionais cuidativas que desconsiderem a situação cotidiana de vida e saúde da pessoa a ser cuidada. Como também não é possível propor tais práticas sem que haja a participação ativa da pessoa sobre a qual irão incidir as decisões e condutas aí tomadas